Sleeping habits have been considered an important factor for the physical and physiological wellbeing of human beings. Bad sleeping habits may lead to many health disorders. Hence, there is a need for monitoring sleep to analyze fitness of human beings.
For example, there is a technique known as ballistocardiography to determine repetitive movements of a human body. Ballistocardiography has been used in art for clinical purposes like monitoring human health, respiration rate and heartbeat etc. Ballistocardiographic measurements comprise measurement of force generated due to the cardiac function of the body, movement due to respiration and other muscle movements of the human being.
There are quite a few systems known in the prior art based on this technique, for example, a US patent application 2010/0016685 discloses a system for detecting body movements using a ballistocardiographic sensor and a noise sensor. However, this patent application does not disclose any means for detecting posture change, or what the posture of a sleeping user is at a given time. This document is incorporated here as reference.
There are also prior art devices known to allege that they detect posture of user while sleeping, for example, there is a RestOn device and application for monitoring sleep of a user, particularly to determine how many times a user has changed posture while sleeping. The RestOn device uses a strip of sensors for this purpose; however, it is not very efficient for determining the exact body posture of the user. This App is publicly available in the Apple iOS App Store. The Techinasia news article is cited here as reference, please see references section.
There are other more complex systems and methods also known in the prior art for monitoring sleep using video recorders and/or radars. For example, US patent application 2007/0156060 discloses a system for automatically monitoring the sleep of a person using a video recorder for recording live images of a subject sleeping. However, such systems are complex and expensive, and not effective during night and/or in dark rooms. Further, realization of such devices as a consumer application is not easy and they may even create hindrance in a user's sleep. This document is also incorporated here as reference.
As seen, none of the available prior art disclosures provide any method of determining the quality of sleep by analyzing the body posture and accurately distinguishing static body posture changes from minor body movements.
In light of the above discussion, there is a need for a system that can overcome one or more problems associated with the prior art.